This invention relates to a cellular stock material having a particular backing structure. More particularly, this invention relates to a sponge cushion underlay for a surface covering, such a as a carpet, and to a method of easily removing the surface covering from a supporting surface, such as a floor or a wall, to which it is adhesively bonded.
Carpeting is usually securely fastened to a floor in order to minimize safety risks and to extend the life of the carpet. The use of an adhesive to firmly bond carpeting to a floor has found widespread acceptance. Carpeting can be easily installed with an adhesive and minimal maintenance is required, since the carpet remains in position even with extended use.
The adhesive must form a strong bond between the carpet and the floor to withstand the heavy compressive loads and lateral forces frequently encountered. For example, furniture, instruments and rolling machinery in residential, institutional and industrial environments can readily induce movement in a carpet that is not firmly bonded to the floor.
It is conventional to install a sponge or foam cushion between the carpet and the floor to enhance comfort and to extend the life of the carpet. The cushion is glued to the floor, and the carpeting is then glued to the cushion. The low cost cushion materials used in making carpet underlays usually have very low tensile strength. Consequently, when the carpet is stripped from the floor for repair or replacement, the sponge or foam is torn apart and a portion of the cushion remains bonded to the floor. Manual removal of the cushion adhering to the floor is not practical for economic reasons.
Thus, there exists a need in the art for a cushion material capable of meeting the conflicting requirements of a carpet underlay. The cushion material must be capable of being securely bonded to a floor to withstand high compressive loads and lateral forces without detaching from the floor. In addition, the cushion must be easily strippable from the floor when the carpet is removed.